Sleep disruption, and daytime sleepiness are frequent complaints of the elderly. Such behavioral symptomology negatively affect the quality of life of older adults and are a major reason for institutionalizations. Growing evidence suggests that disorders in the timing and distribution of sleep commonly seen in this population are associated with age-related changes in the circadian system. Many of the elderly are exposed to limited circadian synchronizing agents such as bright light. This is particularly prevalent in nursing homes and assisted living facilities. Several studies have indicated that timed bright light exposure from natural and artificial sources may be useful in the treatment of sleep- wake cycle disorders and accelerate adaptation to jet-lag and shift work. However, the older population has not adapted well to the existing technologies, which also lack FDA approval. The goals of this program are to develop a portable, light weight innovative, fiber optic, bright light delivery system which utilizes a near-eye, visually transparent light field and to examine the effects of this Personal Light Field ( PLF ) on measures of subjective/objective sleep quality, daytime alertness, and circadian rhythmicity of elderly residents in assisted living facilities. We expect to obtain FDA approval for PLF. PROPOSED COMMERCIAL APPLICATION: Not available.